Water in industrial oils (e.g., turbine oils) is problematic and can cause equipment failure. Accordingly, the oil is periodically analyzed to determine the water content and to schedule equipment oil changes. The usual analysis method is the Karl Fischer coulometric titration method. This method, however, is time consuming, somewhat cumbersome, and requires hazardous reagents, careful sample preparation, expensive equipment, and training.
Infrared spectroscopy, if used to measure the amount of water in oil, can produce inaccurate results. See U.S. Pat. No. 8,068,218 incorporated herein by this reference. Water can scatter the infrared light, the size of the water droplets can vary, and the water can separate from the oil in a sample all leading to variability when infrared spectroscopy is used. In the '218 patent, a surfactant is added to the oil sample to disperse the water in the oil and increase its optical absorbance. Still, the infrared bands associated with water absorbance may be highly variable with the type of oil sample and its chemical state at the time of water ingression.
See also Araujo et al., Evaluation of Water Content and Average Droplet Size in Water-in-Crude Oil Emulsions by Means of Near-Infrared Spectroscopy, Energy and Fuels 2008, pages 3450-3458, by The American Chemical Society (incorporated herein by this reference) where a homogenizer is used to create artificial samples to prove the principle of measuring the amount of water in crude oil in-situ. However in this case the homogenization technique is only used to create representative artificial samples. The oil analyzed was not homogenized.